On Thu, Feb 14, 2019 at 12:25:27PM +0100, Igor Mammedov wrote:
>On Thu, 14 Feb 2019 08:52:25 +0800
>Wei Yang <richardw.y...@linux.intel.com> wrote:
>
>> Currently we do device realization like below:
>>
>> hotplug_handler_pre_plug()
>> dc->realize()
>> hotplug_handler_plug()
>>
>> Before we do device realization and plug, we would allocate necessary
>> resources and check the capacity.
>'capacity' probably is not right word to use here
>maybe s/the capacity/if 'memory-hotplug-support' property is enabled/
>
>>
>> While we leave acpi_memory_hotplug capacity check in the last step. This
>wouldn't use 'leave' and 'capacity' here either, pls rephrase.
>
>> looks not comply with current architecture and does some unnecessary
>s/looks not/doesn't/
>> work.
>add more explanation about 'unnecessary work'.
>problem as I see it, is that after successful pc_dimm_plug()
>we get into piix4_device_plug_cb() and since
> s->acpi_memory_hotplug.is_enabled == false
>and all other 'if' conditions also false we would endup
>at g_assert_not_reached() causing QEMU crash in piix4 case
>and with error_abort up the call chain in case of ich9.
>
Thanks Igor, I rephrase above change log like this. Does this look
better to you now?
Before we do device realization and plug, we would allocate
necessary resources and check if memory-hotplug-support property is
enabled.
In piix4 and ich9, the acpi_memory_hotplug property is checked in
plug stage, this doesn't comply with current architecture. This
means we have prepared everything and even do pc_dimm_plug()
successfuly, but failed at last because
acpi_memory_hotplug.is_enabled == false. Which is worse is in piix4,
this endup at g_assert_not_reached() and cause QEMU crash.
>> This patch abstract the check on acpi_memory_hotplug capacity in
>> pre_plug stage.
>>
>> Signed-off-by: Wei Yang <richardw.y...@linux.intel.com>
>> ---
>> hw/acpi/piix4.c | 14 ++++++++++++--
>> hw/i386/pc.c | 8 ++++++++
>doesn't look complete, why did you skip on similar code in ich9
>(Q35 machine)?
>
You are right, I missed this part.
>> 2 files changed, 20 insertions(+), 2 deletions(-)
>>
>> diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
>> index e330f24c71..c97b747496 100644
>> --- a/hw/acpi/piix4.c
>> +++ b/hw/acpi/piix4.c
>> @@ -370,13 +370,22 @@ static void piix4_pm_powerdown_req(Notifier *n, void
>> *opaque)
>> acpi_pm1_evt_power_down(&s->ar);
>> }
>>
>> +static void piix4_device_pre_plug_cb(HotplugHandler *hotplug_dev,
>> + DeviceState *dev, Error **errp)
>> +{
>> + PIIX4PMState *s = PIIX4_PM(hotplug_dev);
>> +
>> + if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM) &&
>> + !s->acpi_memory_hotplug.is_enabled)
>> + error_setg(errp,
>> + "memory hotplug is not enabled: PIIX4 memory hotplug disabled");
>> +}
>> static void piix4_device_plug_cb(HotplugHandler *hotplug_dev,
>> DeviceState *dev, Error **errp)
>> {
>> PIIX4PMState *s = PIIX4_PM(hotplug_dev);
>>
>> - if (s->acpi_memory_hotplug.is_enabled &&
>> - object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
>> + if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
>> if (object_dynamic_cast(OBJECT(dev), TYPE_NVDIMM)) {
>> nvdimm_acpi_plug_cb(hotplug_dev, dev);
>> } else {
>> @@ -702,6 +711,7 @@ static void piix4_pm_class_init(ObjectClass *klass, void
>> *data)
>> */
>> dc->user_creatable = false;
>> dc->hotpluggable = false;
>> + hc->pre_plug = piix4_device_pre_plug_cb;
>> hc->plug = piix4_device_plug_cb;
>> hc->unplug_request = piix4_device_unplug_request_cb;
>> hc->unplug = piix4_device_unplug_cb;
>> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
>> index 734d3268fa..3c6eed0cd3 100644
>> --- a/hw/i386/pc.c
>> +++ b/hw/i386/pc.c
>> @@ -1662,6 +1662,7 @@ static void pc_memory_pre_plug(HotplugHandler
>> *hotplug_dev, DeviceState *dev,
>> const PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
>> const bool is_nvdimm = object_dynamic_cast(OBJECT(dev), TYPE_NVDIMM);
>> const uint64_t legacy_align = TARGET_PAGE_SIZE;
>> + HotplugHandlerClass *hhc;
>>
>> /*
>> * When -no-acpi is used with Q35 machine type, no ACPI is built,
>> @@ -1674,6 +1675,13 @@ static void pc_memory_pre_plug(HotplugHandler
>> *hotplug_dev, DeviceState *dev,
>> return;
>> }
>>
>> + /*
>> + * Check acpi_dev memory hotplug capacity
>> + */
>> + hhc = HOTPLUG_HANDLER_GET_CLASS(pcms->acpi_dev);
>> + if (hcc->pre_plug)
>> + hhc->pre_plug(HOTPLUG_HANDLER(pcms->acpi_dev), dev, errp);
>use hotplug_handler_pre_plug() instead of open-coding check
>
Thanks, will fix this.
>> if (is_nvdimm && !pcms->acpi_nvdimm_state.is_enabled) {
>> error_setg(errp, "nvdimm is not enabled: missing 'nvdimm' in '-M'");
>> return;
>
--
Wei Yang
Help you, Help me
